Sicarii

The Sicarii were a radical Jewish sect of zealots who were infamous for using assassinations against Roman officials and their Herodian Judean collaborators from the 50s to 70s AD. They pioneered the use of cloaks and daggers, assassinating a target before disappearing into the crowd after the deed to escape detection. In 66 AD, the Sicarii assisted in the takeover of Jerusalem from the Romans, and their leader Menahem ben Yehuda oversaw the massacre of the 700-strong Roman garrison of Masada that same year. However, a string of defeats at the hands of the Romans in 68 AD led to internal strife between the Judean provisional government and the Sicarii, and Menahem was killed during the violence. Eleazar ben Ya'ir and the surviving Zealots holed themselves up in the fortress of Masada, defending it until 73 AD, when they committed mass suicide rather be captured alive.